(John Locher/Las Vegas Review-Journal/Pool/AP Photo)

Vice President Joseph Biden spent the afternoon attempting to woo Hispanic voters to the polls, asking attendees of a Latino advocacy conference to envision the policies of a Mitt Romney White House.

"Imagine what the Supreme Court will look like after four years of a Romney presidency," he said. "Imagine what it will be like. Imagine what it will mean for civil rights, voting rights, and so much more that we have fought so hard for, so long, to accomplish."

Biden was speaking before the annual gala of the National Council of La Raza.

Latino voters support President Obama by commanding margins. Noting the group now makes up 16 percent of the U.S. population, Biden warned, "There are voices among us who fear your inclusion."

He maintained that a Romney Justice Department, would uphold, rather than challenge, what Democrats have dubbed efforts to suppress minority voting rights.

Biden tied the presumptive Republican candidate and his party to Arizona's controversial SB 1070 law, which allows law enforcement to check the immigration status of anyone stopped or arrested.

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"Mitt Romney wants you to show your papers, but he won't show us his," he said.

The statement tangles Romney's tough border stance with calls from critics for the former Massachusetts governor to release more of his past tax returns, an unofficial custom shouldered by most presidential candidates in recent decades. Romney has only made available his 2010 filing.

"When his father was a candidate for president in 1968, his father released 12 years of tax returns because he said, and I quote, 'One year could be a fluke, perhaps done for show.'" Biden said. "His son has released one year of his tax returns."

The vice president said it made "a lie of the old adage: Like father, like son."

Biden also took the time to rip Republican economic proposals, charging that Romney and congressional party members would cut social programs directly impacting Latino communities.

"A policy that would be devastating, not just to your community, but my community, and every community in America," he said.

Romney's campaign offers their own take on Biden's outing with a spokesperson telling ABC News the well being of Latinos had worsened because of the current administration.

"The Hispanic community has been hit disproportionately hard in the Obama economy, with an unemployment rate of 11% and millions more Hispanics living in poverty since he took office," says Amanda Henneberg. "Yet Vice President Biden would rather engage in cynical and dishonest character attacks than discuss how to create jobs and promote opportunity for all Americans."

This post has been updated.